In the interval 1979-1988, out of 1070 operated goiters 77 malignant thyroid tumors were recorded, 60 of them being differentiated: papillary--32 (53.4%), vesicular--12 (20%), mixed forms--16 (26.7%). The differentiated thyroid carcinomas had peculiar clinical biological and prognostic features and were framed: stage I--60%, stage II--23.4% and state III-IV--16.6%. Only 15 cases presented lymph node metastases. In 16 cases the thyroid tumor was associated with another thyropathy: Hashimoto's thyroiditis--5 cases, Basedow's disease--1 case. The surgical intervention was performed in two times: first total lobectomy or total lobo-isthmectomy [correction of lobioistectomy] with contralateral subtotal exeresis, then total thyroidectomy. It is insisted upon a careful surveillance of postoperative evolution (clinical, biological, scintigraphy) in order to detect the recurrence and apply a proper treatment.